1. Technical Field
The present invention relates to a method for producing glue-laminated (gluelam) bamboo timber articles, such as flooring, and more particularly, to a method for producing colored gluelam bamboo timber articles.
2. Related Art
Methods for producing colored gluelam bamboo timber articles, e.g., bamboo flooring, are known in the prior art. For example, Chinese Utility Model Patent No. ZL200520013915.2, publication number CN2811449, discloses a method for making colored bamboo timber flooring that produces a colored, woven-strand type of flooring.
The processing method for coloring these products is as follows. A dyeing liquor is mixed with an adhesive to form a colored glue. Bamboo threads are then immersed in the colored glue and the resulting mixture is then formed in a mold under high-pressure. Alternatively, the bamboo threads are first soaked with the dyeing liquor, then immersed in the adhesive, and then formed in a mold under high-pressure. However the foregoing processes exhibit certain disadvantages, including the following:                In the dyeing process, the dyeing liquor penetrates through the bamboo threads slowly from the surface to the interior, which takes a long time and results in a very uniform coloring of the product in which the natural texture of bamboo is entirely lost and an unnatural color is exhibited;        Since the bamboo flooring must be compressed and formed under high-pressure, typically with a pressure over 50 MPa, large compressing machines with capacities of greater than 2000 tons are required;        Typically, a compressing machine can press only a single, unique size of laminated colored bamboo thread materials; the length of the colored bamboo threads useable is therefore also limited, typically to 1800 mm, because of the size of the workbench of the compressing machine, which therefore restricts the machine's use; in order to increase the useable length, a larger compressing machine is required;        Since a mold is also required in the compressing process, the size of the laminated colored bamboo threads materials is likewise limited to a maximum of about 1800 mm×105 mm×130 mm, due to the size limitations of the mold;        The formed laminated materials have to be split before they can be used, so a splitting machine is also required, which restricts the width of the laminated materials; the maximum practical width of the product is therefore only about 105 mm, due to the limitation of the splitting machines;        The bamboo threads are immersed in the glue, which results in a large joining area with the glue, and consequently, a high glue content of 8˜15% and a high product density of 900˜1300 kg/m3; as a consequence of the high glue content, the bamboo flooring products produced thereby are not environmentally friendly, and in some cases, can even be harmful to the health of consumers;        Due to the high pressures involved in the molding process, most of the pores of the bamboo pores are closed shut during compression; as a result, the laminated bamboo materials can warp easily in humidity, which causes flooring to exhibit a warped surface and bad appearance;        Due to the high-pressure forming process, the moisture inside the laminated materials is not easily removed, so that boards of, e.g., 15 mm thickness, must be dried for at least 45 days before they can be used; the time required by the production process is therefore inherently long and unsuitable for mass production        
As a result of the foregoing and other drawbacks, the prior art methods result in high cost, low yield and low production efficiency.